Least played characters you ask?
Good sir, the better question, is what characters are the only ones played?
Red Underwear over his buttfucking-pants man, black underwear pulled over his arrogant knowitall orphan head man, red underwear over her getting buttfucked-pants girl, big gay red salt monster and his dickless laser lugey-hawking pet cat, and lest we forget, the wonderful super awesome magic suicide bomber.
Those are the ONLY characters played online or off.
Perhaps a few have tested the waters with other lower tiers, but alas, they brought not their floaties, they were not prepared and so had to return to the shallows forevermore.